GeForce GTX 680 is a high-end Graphics Card based on the 28nm, Kepler architecture. The Kepler architecture allows more SPUs but the Fermi SPUs (used on the 400 & 500 Series) are clocked twice as fast as the Kepler architecture. Therefore, don't let the large amount of Pipelines fool you, as the 1536 Pipelines are equivalent to 768 Pipelines, of the Fermi architecture. GeForce GTX 680 features a 1006Mhz core-clock that can automatically set itself to 1058Mhz using a technology similar to the one used on Intel GPUs. Another huge surprise is the TDP that went from 244 Watts, to just 195 Watts, as two SPUs of the Kepler architecture consume 10% less power. However, the amount was doubled and so the power save is not as high as it could have been. GeForce GTX 680 was the fastest single GPU of the world until Radeon HD 7970 GHz Edition was released. All games will run on the maximum settings smoothly.

in my recent researchs, most of the sites said that the 2GB frame buffer does an enormous performance bottleneck in this GPU (for 1080P and beyond) and this is the reason for its poor performance on recent games against lower-end radeons (with 3-4GB) or even the 4GB 960.